A Brooklyn Supreme Court judge has granted a new hearing for a Brooklyn man jailed almost 10 years for a murder he says he didn’t commit.

John Giuca, 31, was sentenced to 25 years to life along with Antonio Russo in 2005 for the fatal shooting of 19-year-old college football player Mark Fisher in Midwood after a night of partying in 2003.

The courtroom was packed with Giuca’s family and friends, who hugged and took pictures after the decision Thursday. Some sobbed with joy.

“This is a good thing,” Giuca’s mother, Doreen Quinn Giuliano, told the throng of supporters. “Now a fair trial can take place.”

“This is what brought us here today,” said an uncle of Giuca’s who would not identify himself as he passed out overviews of the case to bystanders and press.

Fisher was a Fairfield University student on his first unsupervised trip to the city. After drinking with friends on the Upper East Side, he followed a girl to Giuca’s Ditmas Park home, where he allegedly sat on a coffee table and offended Giuca.

He was later shot five times in the torso and neck, reportedly after the group decided his death would bring their feeble gang, the Ghetto Mafia, some street cred.

“A lot of people are still convicted, but what happened today gives me hope,” said Shakur, who was wrongfully imprisoned in 1988 for a double homicide based on the tainted investigative work of retired NYPD Detective Louis Scarcella and freed earlier this year.

“It is the DA office’s responsibility to divulge information. I don’t want to personalize this, but it is her conduct that is in question,” Giuca’s defense attorney, Mark Bederow, said of prosecutor Sigga-Nicolazzi.

“We consented to the hearing. We are standing by the conviction and we are confident that after a fair and thorough proceeding, it will be upheld,” said a spokesperson for the Brooklyn District Attorney’s Office.

Giuca has accused Nicolazzi of brokering a deal for jailhouse snitch John Avitto and failing to disclose that information to the defense. In an affidavit filed in May, Nicolazzi denied misconduct, saying the drug-addicted Avitto came to prosecutors with Giuca’s alleged jailhouse confession because Avitto “wanted to do what was right.”

Prosecutor Anna-Sigga Nicolazzi in 2009.Gregory P. Mango

The prosecutor added that she never promised Avitto leniency in his unrelated burglary case — ­despite the fact he had been facing jail time and came to her months after Fisher’s death.

“On more than one occasion, Avitto stated to me that he was not seeking any benefit from the People in return for his cooperation and testimony at [Giuca’s] trial,” Nicolazzi wrote.

Groups of Giuca’s supporters gathered for photos in front of the courthouse Thursday , including a group of high school friends.

“He’s strong-willed, so he’s doing good,” said Tommy Saleh, 32, who has known Giuca for 17 years.

“He was a good kid —he went to college, was in law school,” said another relative who would not identify himself. “We’re proud of him.”